Introduction

Within Joomla there are manifest files for all of the extensions. These files include the general installation information as well as parameters for the configuration of the extension itself. Since Joomla! 2.5 , there are very few differences between the manifest file formats for the different types of extensions, allowing each type to access the full power of the Joomla! installer.

Naming conventions

The file must be named manifest.xml or <extension_name>.xml and located in the root directory of the installation package.

Syntax

Root element

The primary tag of the installation file is:

<extension></extension>

This starting and closing tags are now valid for all extensions. The new tag <extension> replaces the old <install></install> from Joomla . The following attributes are allowed within the tag:

Attribute

Values

Applicable to

Description

type

componentfilelanguagelibrarymodulepackageplugintemplate

All extensions

This attribute describes the type of the extension for the installer. Based on this type further requirements to sub-tags apply.

version

2.53.0

All extensions

String that identifies the version of Joomla for which this extension is developed.

method

installupgrade

All extensions

The default value install will be also used if the method attribute is not used. The install value means the installer will gracefully stop if it finds any existing file/folder of the new extension.

client

siteadministrator

Modules

The client attribute allows you to specify for which application client the new module is available.

group

string

Plugins

The group name specifies for which group of plugins the new plugin is available. The existing groups are the folder names within the directory /plugins. The installer will create new folder names for group names that do not exist yet.

Metadata

The following elements can be used to insert metadata. None of these elements are required; if they are present, they must be a child of the root element.

Front-end files

Files to copy to the front-end directory should be placed in the <files> element. You can use the optional folder attribute to specify a directory in the ZIP package to copy from. Each file to copy must be represented by a <filename> element. If you want to copy an entire folder at once, you can define it as a <folder>.

Media files

This example will copy the file(s) (/media/com_example_logo.png) and folders ( /media/css/ and /media/js/ ) listed to /media/com_example/, creating the com_example folder if required. You can use the optional folder attribute to specify a directory in the ZIP package to copy from (in this case, media).

Extensions should be storing assets they need to be web accessible (JS, CSS, images etc) in media. Amongst other things this feature was added as step in the progression to multi-site support and the eventual move of code files (PHP) out of the web accessible areas of the server.

Administration section

The administration section is defined in the <administration> element. Since only components apply to both the site and the administrator, only component manifests can include this element.

Back-end files

Files to copy to the back-end directory should be placed in the <files> element under the <administration>. You can use the optional folder attribute to specify a directory in the ZIP package to copy from. See Front-end files for further rules.

Menu links and submenus

The text for the main menu item for the component is defined in the <menu> item, a child of <administration>. A <submenu> element may also be present (also a child of <administration>), which may contain more menu items defined by <menu>.

Additionally, each <menu> item can define the following attributes:

Attribute

Description

link

A link to send the user to when the menu item is clicked

img

The (relative) path to an image (16x16 pixels) to appear beside the menu item.

Must be an url compatible as a file too (e.g. no spaces) !

alt

string

An URL parameter to add to the link. For example, <menu view="cpanel">COM_EXAMPLE</menu> in com_example's XML manifest would cause the URL of the menu item to be index.php?option=com_example&view=cpanel.

The value inside the tag is the menu's label. Unlike Joomla! 1.5, you can not use a natural language string. For example, if you would enter "Example Component" instead of COM_EXAMPLE, it would result in your component name appearing as example-component in the menu and you would be unable to provide a translation. In order to provide a translation you need to create a file named en-GB.com_example.sys.ini in administrator/languages/en-GB (you can use the manifest's tag as shown below. This tag considered to be deprecated since Joomla! 1.6. We encourage you to put extension 's language files in extension folder and Joomla! is responsible for loading of required language files.

Storing extension language files in extension folder, you gain benefit when removing some language from Joomla! installation. As your language files were not removed, when reinstall the language again you can use that files without install them again.

The structure of language folder for frontend and backend is the same. You put them in <language> tag of your folder e.g. language/en-GB/. You have to specify these folders in front-end and back-end files too.

During development you can turn on language debuggin in Joomla! global configuration. So you can investigate if the problems exists.

Script file

<scriptfile>example.script.php</scriptfile>

An optional script file (PHP code that is run before, during and/or after installation, uninstallation and upgrading) can be defined using a <scriptfile> element. This file should contain a class named "<element_name>IntallerScript" where <element_name> is the name of your extension (e.g. com_componentname, mod_modulename, etc.). Plugins requires to state the group (e.g. plgsystempluginname). The structure of the class is as follows:

Update servers can be defined in the <updateservers> element, a child of the root. This element may contain one or more <server> element, each describing a location to fetch updates from. Each <server> item can define the following attributes: